Supply chain efficiency can make a diet more sustainable by reducing food loss, resource use, emissions and waste between production and consumption. However, efficiency alone does not guarantee sustainability; production methods, transport, energy sources and equity also matter.
This is HL-only content in IB ESS subtopic 5.2 Agriculture and food, specifically the sustainability of different diets.
A food supply chain includes production, processing, packaging, storage, transport, retail and consumption. Greater supply chain efficiency delivers usable food with fewer wasted inputs, including land, water, energy and labour.
| Supply chain factor | Effect on dietary sustainability |
|---|---|
| Reduced food loss | Less replacement production, saving land, irrigation, fertilizer and energy. |
| Efficient transport | Full vehicles, optimized routes and rail or shipping can lower emissions per unit delivered. |
| Effective storage | Refrigeration and sealed storage prevent spoilage and improve food security, but cooling consumes energy. |
| Appropriate packaging | Longer shelf life may prevent more impact than packaging creates, but excessive packaging increases waste. |
| Local distribution | It may support livelihoods and resilience, but local food is not automatically low-carbon. |
For example, improved refrigerated cold chains in India can reduce losses of fruit, vegetables and dairy before sale. This can increase food availability and farmers’ incomes, yet fossil-fuelled refrigeration and unequal infrastructure access create environmental and environmental justice concerns.
A common misconception is that fewer “food miles” always mean a more sustainable diet. Distance is only one factor: efficiently shipped food may have a smaller footprint than local food grown in heated greenhouses or using resource-intensive methods.
Exam technique: For an “explain” question, link each improvement to a specific environmental or social outcome. For “evaluate,” weigh reduced waste and improved food security against energy use, packaging, equity and production impacts, then give a supported conclusion using a named example.